Having a quick motion is very important since it helps the quarterback throw the ball with better timing, and a better velocity and also can help avoid sacks on some occasions.
Here is a video of Justin Fields from last year (Top) and from yesterday (Bottom). You can truly see a difference in the quickness of the motion. While it's nothing incredibly glaring, a fraction of a second can make all the difference in the world.
In the same vein, Justin Fields also mentioned that OC Luke Getsy is having him make a couple of minor changes in his dropback:
We knew that Luke Getsy has been proclaimed as a QB "Guru" and it looks like he is living up to his hard-working, technical coaching-style reputation.